perf(transform-ast): one kitchen-sink suite per version pair (~95s → ~12s)

.agents/skills/testing-fixtures/SKILL.md

@@ -168,6 +168,12 @@ npm run kitchen-sink   # generate transform-specific kitchen-sink tests
 npm run test:ast       # run AST round-trip validation
 ```
 
+`make-kitchen-sink.ts` writes `__tests__/kitchen-sink/fixtures.json` (fixture file
+-> statement keys, shared by every version pair) plus one test file per adjacent
+version pair (`13-14.test.ts` … `17-18.test.ts`), each iterating the manifest with
+`it.each`. Keep it that way: a suite per fixture file meant every fixture paid for
+its own Jest module registry, `generated.json` parse, and six WASM parser inits.
+
 ## Changing a Walker
 
 `@pgsql/transform` drives its whole pipeline (schema mapping, routing, qualify,

packages/transform-ast/__tests__/kitchen-sink/13-14.test.ts

@@ -0,0 +1,16 @@
+// DO NOT EDIT BY HAND — generated by scripts/make-kitchen-sink.ts
+import { readFileSync } from 'fs';
+import { join } from 'path';
+
+import { FixtureTestUtils } from '../../test-utils';
+
+const manifest: Record<string, string[]> = JSON.parse(
+  readFileSync(join(__dirname, 'fixtures.json'), 'utf-8')
+);
+const fixtures = new FixtureTestUtils(13, 14);
+
+describe('13-14', () => {
+  it.each(Object.entries(manifest))('%s', async (_name, tests) => {
+    await fixtures.runFixtureTests(tests);
+  });
+});